What the 38103 alarm means

The controller lost communication with the serial measurement board (SMB) in the robot base — position feedback from the absolute encoders is unavailable. This is one of the faults our repair team handles on ABB IRC5 / OmniCore (RobotWare) systems — the cause is usually identifiable within the first on-site inspection.

Most common causes

  • SMB cable disconnected or damaged at the X2 connector or robot base
  • Broken SMB board
  • Resolver/cable damage
  • Corroded or loose connector pins
Field note: the first item on this list is what we find most often on real machines. Check it before you go deeper.

Step-by-step field fix

  1. Power down and reseat the SMB cable at both the cabinet X2 and the robot base
  2. Inspect the cable for damage along the dress pack
  3. Measure continuity and check connector pins for corrosion
  4. Swap in a known-good SMB board if the cable checks out
  5. After repair, update revolution counters and recalibrate if needed
Safety first: never bypass safety circuits or force contactors closed. If the alarm involves E-stop chains, brakes or drive power, and you are not a trained robot technician, contact a professional — wrong moves here can cost you a robot or an injury.

Still stuck? Get an engineer on the phone — right now

Tell us the alarm code, the robot model and what was happening when the alarm came up. Our engineers run these diagnostics every day, and remote diagnosis by phone or video call is free.

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Related Communication alarms

10012 — Guard Stop (Protective Stop) State 10013 — Emergency Stop State 20032 — Revolution Counters Not Updated 50053 — Too Large Revolution Counter Difference 50056 — Joint Collision 50057 — Joint Not Synchronized
Other brands: we also keep field-fix libraries for Yaskawa · Universal Robots · Kawasaki and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the ABB 38103 alarm mean?

The controller lost communication with the serial measurement board (SMB) in the robot base — position feedback from the absolute encoders is unavailable. In field practice it belongs to the communication family of faults.

QCan I clear a ABB 38103 alarm myself?

Sometimes. Work through the step-by-step checks on this page — the first listed cause is what we find most often in the field. If the alarm returns after two attempts, or the fault involves power, brakes or safety circuits, stop and call a qualified robot service engineer.

QHow fast can a Henghuan engineer help?

On-site response in the Pearl River Delta within 30 minutes to 3 hours, across mainland China in 1-3 business days, and worldwide within 2-5 business days. Remote diagnosis by phone/WhatsApp/video is available immediately.

Written by the Henghuan Robotics repair team from field service experience. Alarm descriptions are our own summary for troubleshooting reference and may vary by controller and software version — when in doubt, check your ABB documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by ABB.